Glassy polymers matrix

Figure 3.4 Mechanism of reinforcement by rubber particles in a glassy polymer matrix...

Anew experimental method based on the polarization-selective photochromic reactions is proposed to monitor extremely slow reorientation dynamics of molecular tracers in glassy polymer matrix. The correlations between the local relaxation processes of polymers and the reorientation dynamics of the tracers with different sizes are found from the experimental results obtained by this method. 

It is generally accepted that mass transport in dense polymer membranes takes place according to the well-known solution-diffusion mechanism [18,19]. For non-swelling and non-plasticizing species the amount of penetrant that can dissolve in the glassy polymer matrix depends on the available sorption sites and often a typical dual mode sorption behaviour is observed [20]. The number of Langmuir sorption sites is strongly related to the free volume distribution of the sample. 

Effect of Glassy Polymer Matrix Phase on Impact Strength... 

The optimum morphology is another property necessary for good impact strengths of two-phase polymer systems. According to a theory that attributes improved impact resistance to the presence of rubbery particles, it is necessary to obtain a solid dispersion made of rubber particles of 1000-2000 nm in diameter within the glassy polymer matrix, as shown in Fig. 3.4 [44]. On the other hand, another theory assumes that the rubbery modifier functions as a continuous lattice-like phase having a honeycomb structure [45-47]. If the... 

Fig. 3.6. Fibrillar structure formed in the interface regions between rubber particles and glassy polymer matrix [76].

Trancong, Q., Chikaki, S., and Kanato, H. (1994) Relationship between reori-entational motions of a photochromic dopant and local relaxation processes of a glassy polymer matrix. Polymer, 35, 4465-4469. 

The sorption isotherms for ethanol and methanol reported in Figure 4 and 5 cannot be interpreted on the basis of the well known dual mode model (/,2). This model assumes that the penetrant content in the glassy polymer matrix may be expressed as fimction of pressure through the sum of two contributions the first refers to the penetrant molecules which are considered to be adsorbed onto the surface of microvoids in the interior of the solid polymer, and the second represents the contribution due to penetrant molecules which are strictly dissolved into the solid phase. In the original formulation of the dual mode model the first contribution is expressed as fimction of pressure in terms of the Langmuir equation and the second through Henry s law. 

In accordance with the above-considered supramolecular scheme of the photoprocess, additive compounds, occurring in heterogeneous struetural zones of glassy polymer matrix, aequire imequal physical properties. This faet is elearly displayed in unequal ability of aromatic compoimds to phosphoresce, if they are injected to glassy films by different methods, namely, from combined solution by volatile solvent evaporation (films 1) and by additive absorption from the vapor phase (films 2). In this connection, tests on photoexeitation of phosphoreseence of naphthalene, a-naphthol and diphenyl in CTA and PMMA films, placed to the inert gas CO2, may be the demonstrative experiment [10]. 

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